| Title: |
Search for Extremely-High-Energy Neutrinos and First Constraints on the Ultrahigh-Energy Cosmic-Ray Proton Fraction with IceCube |
| Authors: |
Abbasi, R; Ackermann, M; Adams, J; Agarwalla, SK; Aguilar, JA; Ahlers, M; Alameddine, JM; Amin, NM; Andeen, K; Argüelles, C; Ashida, Y; Athanasiadou, S; Axani, SN; Babu, R; Bai, X; V., A Balagopal; Baricevic, M; Barwick, SW; Bash, S; Basu, V; Bay, R; Beatty, JJ; Tjus, J Becker; Beise, J; Bellenghi, C; BenZvi, S; Berley, D; Bernardini, E; Besson, DZ; Blaufuss, E; Bloom, L; Blot, S; Bontempo, F; Motzkin, JY Book; Meneguolo, C Boscolo; Böser, S; Botner, O; Böttcher, J; Braun, J; Brinson, B; Brisson-Tsavoussis, Z; Brostean-Kaiser, J; Brusa, L; Burley, RT; Butterfield, D; Campana, MA; Caracas, I; Carloni, K; Carpio, J; Chattopadhyay, S; Chau, N; Chen, Z; Chirkin, D; Choi, S; Clark, BA; Coleman, A; Coleman, P; Collin, GH; Connolly, A; Conrad, JM; Corley, R; Cowen, DF; De Clercq, C; DeLaunay, JJ; Delgado, D; Deng, S; Desai, A; Desiati, P; de Vries, KD; de Wasseige, G; DeYoung, T; Diaz, A; Díaz-Vélez, JC; Dierichs, P; Dittmer, M; Domi, A; Draper, L; Dujmovic, H; Durnford, D; Dutta, K; DuVernois, MA; Ehrhardt, T; Eidenschink, L; Eimer, A; Eller, P; Ellinger, E; Mentawi, S El; Elsässer, D; Engel, R; Erpenbeck, H; Esmail, W; Evans, J; Evenson, PA; Fan, KL; Fang, K; Farrag, K; Fazely, AR; Fedynitch, A; Feigl, N; Fiedlschuster, S |
| Source: |
Physical Review Letters, vol 135, iss 3 |
| Publisher Information: |
eScholarship, University of California |
| Publication Year: |
2025 |
| Collection: |
University of California: eScholarship |
| Subject Terms: |
5106 Nuclear and Plasma Physics (for-2020); 5107 Particle and High Energy Physics (for-2020); 51 Physical Sciences (for-2020); IceCube Collaboration; 01 Mathematical Sciences (for); 02 Physical Sciences (for); 09 Engineering (for); General Physics (science-metrix); 40 Engineering (for-2020); 49 Mathematical sciences (for-2020) |
| Description: |
We present a search for the diffuse extremely-high-energy neutrino flux using 12.6years of IceCube data. The nonobservation of neutrinos with energies well above 10PeV constrains the all-flavor neutrino flux at 10^{18} eV to a level of E^{2}Φ_{ν_{e}+ν_{μ}+ν_{τ}}≃10^{-8} GeV cm^{-2} s^{-1} sr^{-1}, the most stringent limit to date. Using these data, we constrain the proton fraction of ultrahigh-energy cosmic rays (UHECRs) above ≃30 EeV to be ≲70% (at 90% CL) if the cosmological evolution of the sources is comparable to or stronger than the star formation rate. This is the first result to disfavor the "proton-only" hypothesis for UHECR in this evolution regime using neutrino data. This result complements direct air-shower measurements by being insensitive to uncertainties associated with hadronic interaction models. We also evaluate the tension between IceCube's nonobservation and the ∼200 PeV KM3NeT neutrino candidate (KM3-230213A), finding it to be ∼2.9σ based on a joint-livetime fit between neutrino datasets. |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
unknown |
| Relation: |
qt8zn8k45v; https://escholarship.org/uc/item/8zn8k45v; https://escholarship.org/content/qt8zn8k45v/qt8zn8k45v.pdf |
| DOI: |
10.1103/physrevlett.135.031001 |
| Availability: |
https://escholarship.org/uc/item/8zn8k45v; https://escholarship.org/content/qt8zn8k45v/qt8zn8k45v.pdf; https://doi.org/10.1103/physrevlett.135.031001 |
| Rights: |
CC-BY |
| Accession Number: |
edsbas.4B7B17D2 |
| Database: |
BASE |